As shown in FIG. 12, a plurality of wire harnesses are used in a vehicle for connecting many electric and electronic apparatuses. Among the wire harnesses, a wire harness positioned in a vertical direction of the vehicle has a divided intermediate part for easier assembly. Relay 200 is connected to the divided parts. Load 300 is operated in accordance with a switching signal of switch 400 by a controller. In a switching operation by a low current of the controller, power is stably supplied to load 300 operating by AC through relay 200.
As shown in FIG. 1, a plurality of relays are combined, including a common relay system, to implement combined contact types in a relay. One such relay is a multi-contact electromagnetic relay combined with a double make-type relay and a one make-type relay in a base terminal.
However, as the functions of electric and electronic apparatuses in a vehicle become more complicated, a circuit is generally constructed based on a BCM (Body Control Module). The BCM is capable of receiving a plurality of switching signals, and then controlling a plurality of relays based on an on and off operation by interpreting the switching signals. In the past, a turn signal switch, an emergency light signal, and a robbery alarming function were connected to a turn signal lamp relay so that switches and wire connections were very mechanically and electronically complicated. Nowadays, the signals of all switches are inputted into the BCM, and the BCM interprets the sequences of the signals and controls two turn signal relays.
This makes the BCM is becomes a convenient apparatus for vehicles. The BCM is designed to perform various functions such as power window control, wiper motor control, door lock actuator control, robbery prevention control, and room lamp control. The BCM includes a microcomputer having a specific program and a communication electronic device for communication with a LCU (Local Control Unit). There are, however, limits to the BCM's applications. Development of a relay construction in which one relay forms a plurality of load circuits in the vehicle using the BCM is urgently needed.